This invention relates to novel water soluble hydrophobically modified polycarboxylate polymers which are useful as builders in detergent compositions.
The use of builders to improve the overall detergency effectiveness and the whitening power of detergent formulations is well known to those skilled in the art. Typically, builders have been used among other things, as sequestering agents to remove metallic ions such as calcium or magnesium (or the "hardness") from the washing fluid, to provide solubilization of water insoluble materials, to promote soil suspension to retard soil redeposition and to provide alkalinity. The multiple roles played by the builder, as well as the ever changing demands of both household and industrial consumers tend to make formulating detergent compositions a difficult and sometimes complex process.
Polyphosphate compounds, such as tripolyphosphates and pyrophosphates are widely used as builders in detergent compositions, in part because of their ability in sequestering hardness ions. While the use of such phosphate compounds have been very effective, environmental concerns have mounted regarding their possible contribution to the growth of algae in lakes and streams and the resulting eutrophication of such bodies of water. This concern has caused significant legislative pressure to lower or discontinue the use of phosphates in detergent compositions to control pollution. Thus, detergent manufacturers continue to search for effective, non-phosphate detergent builders.
Various alternatives to phosphate builders have been tried and used by detergent formulators. Some of the non-phosphate builders which have been used include citrates, zeolites, silicates, carbonates and a number of organic builders. Among the materials that have been suggested for use in detergent builders are the carboxylated bicyclic compounds and salts thereof disclosed in U.S. Pat. No. 3,898,034 issued Aug. 5, 1975; water soluble co-polymers of unsaturated mono- and dicarboxylic acids with specific block alkylene oxide units disclosed in U.S. Pat. No. 4,559,159 issued Dec. 17, 1985; ether carboxylates shown in U.S. Pat. No. 4,663,071 issued May 5, 1987; copolymers of maleic anhydride and sulfonated styrene or 2-acrylamido-2-methyl propane sulfonic acid disclosed in U.S. Pat. No. 4,711,740 issued Dec. 8, 1987; and water soluble polymers of ethylenically unsaturated monocarboxylic acids and their salts which contain a pendant surfactant linked to the backbone through an ester or carbamate group disclosed in U.S. Pat. No. 4,797,223 issued Jan. 10, 1989.
Notwithstanding the existence of the foregoing types of detergent builders and the advances which have been made in reducing the amount of water-eutrophying phosphate builders in detergent compositions, there remains a continuing need to identify additional non-phosphorous sequestering agents, particularly those which are useful in liquid detergents. Accordingly, it is an object of this invention to provide detergent compositions employing effective, non-phosphate builders as a replacement, in whole, or in part, for phosphate builders.
It is a further object of this invention to provide novel water soluble and/or water dispersible hydrophobically modified polycarboxylate polymers which are useful as detergent builders.